RocksDB: support of out-of-core ? related performance?

Question

I'm starting a new software that should be able to handle large dataset, ie, some terabytes of data.

I have seen that Rocksdb allows storage of large datasets, but I'm not sure it is an out-of-core feature? I mean, if the dataset is larger than the computer RAM, will it handle it?

Also, in case there is no swapping, is there some performance impact study about using such in-memory data store? Thanks

Answer 1

RocksDB has no difficulty with datasets that exceed RAM size. However, you pretty much have to use Bloom filters to preserve performance, and they take up RAM. So you will see some linear memory growth as your database grows. But it's nowhere near 1-to-1, more like 1/50th or so.